The present invention relates to a method of driving a powdery material into a porous material and, more particularly, to a method of driving powdery particles into interconnected voids in a porous material such as open cell cellular materials or fabric materials.
As is well known to those skilled in the art, two types of porous material are generally available depending upon the pattern of distribution of the gas phase in voids or pockets which are generally called cells, open-celled and closed-celled. The open-celled material is known as having the cells interconnected in such a manner that gas may pass from one to another, whereas the closed-celled material is known as a material wherein the cells are discrete and the gas phase of each is independent of that of the other cells. Of these two types of porous material, it is the open-celled material to which the present invention is directed.
The open-celled material to which the present invention is directed is porous material, such as open cell cellular materials or fabric materials.
Heretofore, two methods have been widely used in distributing powdery particles in interconnected cells of a porous material. One method utilizes a high pressure necessary to drive the powdery material into the porous material in a direction in which the high pressure is applied, and the other method utilizes a suction force necessary to draw the powdery material into the porous material from one of the opposite surfaces of the porous material towards the other in a direction in which air is drawn.
The practice of any one of these prior art methods requires the employment of a recovery equipment for recovering some of the powdery particles which have completely passed through the thickness of the porous material, and therefore requires a relatively large space for installation of such recovery equipment. Moreover, in view of the fact that some of the powdery particles tend to pass completely through the thickness of the porous material, no substantial uniform distribution of the powdery particles in the porous material can be achieved with no difficulty and this is particularly true of the case where the powdery particles are desired to be distributed over a relatively large surface area in the porous material.
However, the Japanese Patent Laid-open Publication published on June 21, 1975 under No. 50-76181 suggests the possibility of utilization of vibrations for causing the powdery particles to be permeated into the porous material of an open-celled structure, but has failed to disclose a concrete method and equipment necessary to achieve it.